Refrigerating apparatus



Dec. 10, 1940. D. E. DASHER BEFRIGERATING APPARATUS Filed July 31, 19374 Sheets-Sheet 1 I INVENTOR.

ATTORNEYS Dec. 10, 1940.

ZINViJTOR. BY

ATTORNEYS D. E. DASHER REFRIGERATING APPARATUS Filed July 51, 19374'Sheets-Sheet 5 v ATTORNEYS Dec. 10, 1940. D. E. DASHER REFRIGERATINGAPPARATUS Filed July 31, 1937 4 Sheets-Sheet 4 ATTORNEYS PatentedDec.10, 1 940 UNITED STATES REFRIGERATING APPARATUS Don E. Dasher, Dayton,Ohio, assignor to General Motors Corporation, Dayton, Ohio, acorporation of Delaware Application July 31, 1937, Serial No. 156,770

10 Claims.

This invention relates to refrigerating-apparatus and more particularlyto generator-absorbers particularly of the solid absorbent type.

Heretofore, generator-absorbers of the solid absorbent type have beenlargely made up of finned structures which depended upon carrying theheat of conduction longitudinally through metal from the heating fluidto the absorber. In such a structure, however, the heat transfer both I"in heating and cooling the absorber is relatively slower.

It is an object of my invention to provide a generator absorbing meanswherein a more direct heat flow may be obtained between all the It isanother object of my invention to provide a generator-absorber in whichthe path for heat transfer between all the solid. absorbent and theheating and cooling fluid is very short.

It is still another object of my invention to provide agenerator-absorber means in which the absorbent is cased within .thinmembers, the

greater part of which may be surrounded by a heat transfer fluid.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred form of the present invention is clearlyshown.

In the drawings:

Fig. 1 is a diagrammatic representation of a refrigerating systemincluding a generator-absorber unit embodying my invention;

Fig. 2 is a vertical sectional view through the generator-absorber takenalong the lines 2-2 of Fig. 4;

Fig. 3 is an enlarged sectional view of a portion of thegenerator-absorber taken along the lines 4--4 of Fig. 2;

Fig. 4 is a view partly in section taken along the lines 44 of Fig. 2;

' Fig. 5 is a sectional view taken along the lines 5-5 of Fig. 4;

Fig. 6 is a sectional view of a portion of the generator-absorber takenalong the lines 6-6 of Fig. 2;

Fig. 7 is a sectional view of a modified form of generator-absorber;

Fig. 8 is an end view of an intermediate section of thegenerator-absorber shown in Fig.v 7;

Fig. 9 is a sectional view taken along the lines I 3-9 of Fig. 8;

Flg.'l0 is a sectional view of another improved generator-absorberconstruction taken along the absorbent and the heating and coolingfluid..

Fig. 11 is a sectional view taken along the lines ll-ll of Fig. and

Fig. 12 is a sectional view of several plates taken along the lines I11-40 of Fig. 11.

Briefly, I have shown a refrigerating system 5 of the solid absorptiontype in which the absorber is made up of a plurality of metal plateshaving central apertures, the plates being alternately joined togetherat the edges of their apertures and at their outer peripheries. Theseplates are 10 slightly spaced to provide a space for holding theabsorbent and another space through which the heat transfer fluid maypass.

Referring now to the drawings and more particularly to Fig. 1, there isshown a simple absorption refrigerating system of the solid adsorbenttype including an absorber containing a solid absorbent which is'heatedby a gas burner 22 to cause ammonia or other volatile liquid in the formof a gas to be driven from the solid absorbent and condensed within acondenser 24 shown diagrammatically where the compressed refrigerant iscondensed and supplied through conduit means 26 and 28 under the controlof a suitable valve 29 to an evaporating means 30 located within acompartment 32 to be cooled.-

The gas is supplied under the control of a pressure regulating valve 34and a gas valve 36 to the burner 22. The gas valve 36 is operated by athermostat bulb 38 located within the interior of thegenerator-absorber. When the generatorabsorber reaches a predeterminedtemperature, th gas valve is closed by reason of the high pressurecreated within the thermostat bulb 38. The generator-absorber 20 thencools and absorbs refrigerant in vapor form which returns from theevaporator 30 through the same conduits 28 and 26 as well as thecondenser 24. The gas valve is prevented from closing by an interlockmechanism 4|] which is responsive to the refrigerant pressure within theconduit means 26. When a predetermined pressure is reached within theconduit means 26, the interlock mechanism releases the gas valve 36 andallows it to close in order to start a new generating cycle.

Referring now more particularly to Figs. 2 to 6, inclusive, one form ofthe generator-absorber 20 is shown mainly made up of a plurality ofstacked metal plates best shown in Figs. 3 and '6. In this-form,identical plates are tm'ned toward 5 each other inpairs such as theplates 42 and 44. These plates are each provided with an aperture 46 intheir central portions, and surrounding this aperture 46 these platesare each deformed to provide a flanged portion 48, the two flanges 48fitting together around the aperture. Around this flanged portion theplates are spaced to provide a space 58 through which the gases from thefuel burner 22 may pass. Surrounding this space 58, the plates aredeformed to provide two long arc-shaped projections 52 and 54 I as wellas two small round projections 56 and 58, all of which fit together asshown in Figs. 3 and 6.

The plates 42 and 44 are also spaced surrounding the projections 52 to58 to provide agas space 68 at their edges. The plates 42 and 44 aredeformed to provide flanges 66 and 68 which extend away from each other.At-the extreme edge of these plates, cuts are made about half way in theflanges to provide tongues of metal which are bent toward each other toprovide the spacing projections 62 and 64 which fit together to preservethe spacing between the edge portions of the plates 42 and 44.

The flange 66 rests against the flange 18 of the adjacent plate I2 whichis formed similarly to the plates 68 and 68 and occupies a positioncorresponding to the plate 44. The plate 12 fits against the innerflange and the projections of another similar plate I4 which ispositioned similarly to the plate 42. These plates are further built upin this manner and stacked together until a sufiicient number isobtained to provide adequate capacity for the amount of solidabsorbentrequired for the apparatus. i

For a household refrigerator, enough of these plates are stackedtogether to make an assembly about 16 or 18 inches long. Upon the endsof these stacked members, there is provided end members I6 and I8 whichare formed of heavy sheet metal and contain splitcollars88 and 82surrounding which steel wool designated by the reference characters 84and 86 is provided. This entire assembly is then copper hydrogen brazedto cause the inner and outer flanges as well as the projections to bethermally joined together by a metallic bond.

One of the headers is provided with an inlet 88, and the entire assemblyis tested with a fluid under pressure to detect any leaks which mightarise due to faulty brazing. At the same time the assembly is expandedby a'pressure within the assembly which tends to spread the plates; andwhen the assembly is at its proper length bars 98 having heads 92 at oneend are slipped through apertures at the flanges of the end members I6and 18, and the opposite end is welded as shown at 94 in order toprevent the plates from.

spreading under pressure.

After this, the assembly is placed in a vertical position and rotatedwhile the solid absorbent is poured into the central apertures 46. Thiscauses the absorbent to be thrown out by centrifugal force into thespaces between the plates such as between the plate 42 and the plate 12.Preferably, the absorbent used is strontium bromide, strontium chloride,or magnesium chloride with lithium nitrate.

After this, the absorbent is cleared out of the space along theapertures in the metal plates, and an inner tube 96 is welded at itsends to the headers. This tube is surrounded by eight flat staves 98which are held within two asbestos socks or tubes I82 and I84. The endsof these socks are wrapped with. wire designated by the referencecharacter I86. The purpose of the staves and asbestos socks is toprovide a passage through which the refrigerant in vapor form mayreadily flow from all the absorbent to the space opening I 88 to thespace containing the steel wool let 88. The asbestos sock and the steelwool both act as filters. The sock prevents the absorbent from leavingits place in the absorber, while the steel wool prevents any foreignmatter from entering the absorbent space of the absorber.

Surrounding the absorber is a shroud which has metal members H8 and H2slightly spaced away from the edges of the metal plates. An opening isleft at the top between the two metal members of the shroud for theescape of the products of combustion. The bottoms of the shroud membersH8 and H2 are curled outwardly to form the flanges H4 and H6. Anothersheet metal member H8 is provided with flanges I28 and I22 which maybespot welded or otherwise I fastened by these flanges to the flanges H4and H6. This member H8 provides a combustion space for the flame I24which issues from the gas burner 22. The lower portion of the gas burneris supported by another metal member I26 which is fastened to the memberH8. The

secondary air supply enters through this member I26 and passes into thecombustion chamber I28 through an aperture I38 in the member H8 .I'heplate I42 is provided with a flange I44 which fits into-the apertureprovided in the central portion of the plate 148. This flange I44 isturned or spun over to lock the inner flanges of the plates I48 and I42together. The outer edges of the plates I48 and I42 are provided withflanges I46 and I 48 which are similar to the flanges in the firstmodification excepting that the flange I46 has an additional laterallyturned flange I58 which is adapted to receive the flange I52 of theadjacent metal plate I54 which is similar to the plate I 42. Otherwise,the plates are similar to the plates in the first modification and havea central aperture I56 surrounded by flanges I58 which fit together,whichin turn are surrounded by a space I68 through which the products ofcombustion may pass.

There is also another space I62 upon the outside of the plates throughwhich the-products of combustion may pass. Similar projections I64, I66,I68, and I18 are provided for the interior of the metal plates; but, inaddition thereto, small projections H2 are distributed uniformly aroundthe outer edges of the plates in order to serveas the spacing means andto provide an increased bonding surface to hold the plates together.

After the plates are stamped upon a punch press, they are assembled inpairs and the flange I44 is turned over to lock the pairs at theirapertures] These pairs of plates are then stacked together with theflanges of one set of plates fitting into the turned flanges of theadjacent pair of plates. Enough of these pairs of plates are stackedtogether to form an absorberof suitable size; and, thereafter, the endplates "4 and I16 are assembled onto the ends of the stacked pairs ofmetal plates. These end plates are of a rounded annular shape in orderto withstand high internal pressure- These end plates "4 and H6 areprovided with split collars I18 and I88 as well as the steel wool I82.The end plate I14 is provided with an outlet I15. This assembly is thencopper hydrogen brazed; and, thereafter, the assembly is tested bypressure. When expanded to the proper size,

5 the bars I84 are welded at their opposite ends to the end members I"and HG in order to prevent the plates from spreading. The assembly isthen centrifugally charged with a suitable absorbent such as theabsorbents mentioned in connection l0 with the first modification. Afterthis the inner tube I88 is inserted in place and welded at its ends tothe end plate. This inner tube I88 has a knurled or grooved outersurface I88 through which the refrigerant vapor may pass. This tube I88is surrounded by an asbestos sock I90 or a sock of glass wool fabricwhich is wrapped at its ends with copper wire designated by referencecharacter I92. Instead of employing a sock, the inner tube I86 may bewrapped spirally with glass wool or asbestos fabric and bound with wire.

In Figs. 10, 11, and 12 I have shown another form of generator-absorber20. In this form the pairs of apertured plates such as the plates 2IIland 2I2 are each deformed to provide abutting inner flanges which arelocked together by turning the inner flange of the plate 2I2 over theinner flange of the plate 2I8 as shown at 2I4. Surrounding these innerflanges are a circle of 80 ten projections 2H5 which are formed in eachmember of every pair of plates and which are sufliciently long so thatwhen the plates are assembled and locked as shown at 2 the projections2I8 will flt together. Surrounding the circle a of projections 2"; isanother circle of ten projections 2; which will also fit together toform spacing and bonding portions for the pairs of metal plates. Thesepairs of metal plates are provided with outwardly turned flanges 228 and7 222. The flange 222 of the plate 2I2 has no lat- .erally turnedportion but the flange 228 has a laterally turned portion 224 whichreceives the plain flange 228 of the adjacent metal plate 228, which islike the plate 2I2. and with the plate 238 forms a pair of metal plateswhich are locked together as shownat 232 in a manner similar to thelocking shown at 2I4.

Pairs or setsof plates are first assembled by locking the one plate toits mate as shown at 2 and 2 82 and thenthe pairs or sets are stackedupon one another as shown in Figs. 18 and 12in suflicient number toprovide an absorber of suitable size. w set fits into the laterallyturned flange of the adjacent set. After these sets of plates arestacked together they are provided with end plates 234 and 236 formed ofsheet metal in the shape of a split hollow ring. This assembly is copperhydrogen brazed and then tested for leaks under pressure.

At this time the assembly is brought te the correct length and thelongitudinal bars 238 are welded to the end members 234 and 238 at theiropposite ends to prevent the assembly from 05 spreading. After this, theend members 234 and 238 are filled with steel wool designated by thereference character 248, after which the spaces 7 between the lockedsets of plates are filled with t1 e absorbent material by a centrifugalprocess.

After the spaces between the pairs or sets' of plates are filled withabsorbent a hole is made in the center of the absorbent in the assemblyand an-inner tube 242 including its assembly is inserted and welded inplace at both ends of the wells 244 and 248.

In each case the plain flange of one This inner tube 242 differs fromthe other inv ner tubes in that it serves as the inlet and therefore isprovided with a plug 248 at its smaller end which is provided with alongitudinal inlet passage 258 and a transverse inlet passage 252 5which extends through the .walls of the inner tube. The inner tube 242is wrapped spirally with flat wire or strip 254 which previously to thewrapping has been bent at intervals so that when it is wrapped upon theinner tube it will form itself into 'a hexagonal shape thereon. Thisprovides the free longitudinal passage for the refrigerant gases so thatthey may distribute themselves evenly into the absorbent, Surrounding 15this wrapping of flat wire or strip are two asbestos or glass wool socks256 which serve as a filter to prevent the absorbent fromentering thelongitudinal passage formed by the flat wire strip member 254. The endsof these socks are fastened by 20 wire wrapped around them. With thisassembly, it will be noted that the absorber proper is completed. Afterthat the shroud for the combustion system is applied.

In this form, as well as the other forms, the 25 absorbent is heldbetween closely spaced metal plates such as the metal plates 2II'I and228 which transfer conditions, since practically all the ab- 35,

sorbent is located less than the distance of onehalf the spacing of themetal plates from the nearest cooling air or cooling fluid. Likewise,during the heating period, the products of combustion may passuponsubstantially all of the 40 outer surface of the metal plates sothat efficient heating also results. In this way, the cooling of theabsorber is much more rapid and etficient; and the heating is also morerapid and emcient. This overcomes the major obstacle in the manu- 45facture of generator-absorbers for solid absorbents since it makes itpossible to obtain relatively good heat transfer conditions when a solidabsorbent is employed. I I

While the form of embodiment of the inven- 50 tion as herein disclosed,constitutes a preferred form, it is to be understood that otherformsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows: 68

1. An absorber comprising a plurality of metal plates havingsubstantially centrally located apertures therein, the plates beingalternately joined directly together at the edges of their apertures andadjacent their outer peripheries, '80 said platesbeing slightly spacedin between the joined portions, the interior of the plate constructionbeingfilled with a solid absorbent material located between the plates.

v 2. An absorber comprising a plurality of metal plates havingsubstantially centrally located apertures therein, the plates beingalternatelyjoined together at the edges of their apertures and adjacenttheir outer peripheries, said plates being slightly spaced in betweenthe joined por- 70 tions, the interior of the plate construction beingfilled withan absorbent material located between the plates, saidplatesbeing-provided with projections, said projections being joinedto-. gether for preventing the spreadingof the plates. I6

joined together at the edges of their apertures and adjacent their outerperipheries, said plates being slightly spaced in between the joinedportions, a tubularmember extending through said centrally locatedapertures, and an absorbent located between said tubular member and themetal plates.

5. An absorber comprising a plurality of metal plates havingsubstantially centrally located apertures therein, the plates beingalternately joined together at the edges of their apertures and adjacenttheir outer peripheries, said plates being slightly spaced in betweenthe joined portions, a tubular member extending through said centrallylocated apertures, an absorbent located between said tubular member andthe metal plates, and means providing passages along the tubular member.

6. An absorber comprising a plurality of metal plates havingsubstantially centrally located apertures therein, the plates beingalternately joined together at the edges of their apertures and adjacenttheir outer peripheries, saidl plates being slightly spaced in betweenthe joined portions, the interior of the plate construction being filledwith an absorbent material located between the plates, end members atthe opposite ends of said metal plates, bars joining said end members onthe outside of said plates, and a tubular member extending through thecentrally located apertures in said plates to join the end members.

'7. An absorber comprising a plurality of metal plates having aperturestherein, the plates being alternately joined together at the edges oftheir apertures and adjacent their outer-peripheries,

said plates being slightly spacedin between the joined portions, theinterior of the plate construction being filled with an absorbentmaterial located between the plates, end members at the opposite ends ofsaid metal plates, bars joining said end members on the outside of saidplates,

a tubular member extending through the apertures in said plates to jointhe end members, and means providing passages along the tubular memberincluding a fabric member of an inorganic material.

8. An absorber comprising a plurality of metal plates having aperturestherein, the plates being alternately joined together at the edgesoftheir apertures and adjacent their outer peripheries, said plates beingslightly spaced in between the joined portions, the interior of theplate construction being filled with an absorbent material locatedbetween the plates, a tubular member extending through said apertures,said tubular member being smaller than said apertures to provide forcommunication between the interior of the plate construction.

9. An absorber comprising a plurality of metal plates havingsubstantiallycentrally located apertures therein, the plates beingalternately joined together at the edges of their apertures and adjacenttheir outer peripheries, said plates being slightly spaced in betweenthe joined portions, the interior of the plate construction being filledwith an absorbent material located between the plates, said absorberhaving end plates at its opposite ends, said end plates being joined tosaid metal plates adjacent their outer peripheries, said end plates eachbeing provided with a substantially centrally located aperture, atubular member connecting the aperture located in the end plates andextending through the centrally located apertures in said metal plates,the apertures in said metal plates being larger than the outside of saidtube to permit the passage of gases along the tube.

10. A heat transfer means comprising a plurality of metal plates havingapertures therein,

the plates being alternately joined together at the edges of theirapertures and adjacent their outer peripheries, said plates being spacedclose together but. separated slightly, a member extending through saidapertures, said member being smaller than said apertures to providecommunication between the various spaces enclosed between the plates,said plates being also provided with distributed projections near theiredge portions, means for joining the projections of those adjacentplates which are unconnected at their outer peripheries to preventspreading of the plates, and means cooperating with the outside platesof the plurality of plates and with said member to seal the spacebetween said member and said plurality of plates.

' DON E. DASHER.

